After a breakup, require the companies to not merge for decades?

Have a theory on corporate organization for cases of industries where there is heavy capital investment to enter, but low marginal cost. A cooperative style organization where regional sellers can freely enter or join, but cannot do business with each other. The cooperative would own in the case of telecommunications the backbone, and the research labs (if research is needed that the regional companies cannot afford themselves). So that it won’t be a franchised monopoly, the cooperative doesn’t have patent or trade secret rights, it can’t sue competitors out of existence.

Influenced by mutualism.

Market share tax just results in companies redefining their industry.